Compressible Flow Calculator

This calculator is an aid in making calculations in compressible fluid dynamics, such as isentropic flow, normal shock, oblique shock, Rayleigh and Fanno flow. A page allows computation of the standard atmosphere at a given altitude and Mach number.

There are several colored buttons across the top of the form. If you click on a button, a computing page appears for the desired calculation. There will be one or more input boxes to be filled in and choices that can be made about which input quantity is to be specified.

After making your choices, click the Compute button and the desired results will appear in a window.

You may dismiss the calculator by closing the browser tab.

To return to this page, press the Main Page button.

To go to the Public Domain Aeronautical Software home page, click here.

Ratio of Specific Heats (gamma)

You may set the value of gamma, the ratio of specific heats of the gas to be computed. The default value is 1.4

Isentropic Flow

Select the input quantity. Then type the value of the desired quantity in the input box. Finally, click (or tap) the Compute button to display the Output. Illegal values will be flagged with error messages.

Input Quantity Output data
Mach number, M =
compressibility factor, β =
pressure ratio, p/pt=
temperature ratio, T / Tt =
density ratio, ρ / ρ t =
q static ratio, q/p=
q total ratio, q/pt=
velocity ratio, V / a* =
area ratio, A / A* =
Prandtl-Meyer angle, deg.=
Mach angle =
gamma =

Normal Shock

Select the input quantity. Then type the value of the desired quantity in the input box. Finally, click (or tap) the Compute button to display the Output. Illegal values will be flagged with error messages.

Input Quantity Output Data
Upstream Mach number, M1=
Downstream Mach Number, M2=
total pressure ratio, pt2/pt1=
static pressure ratio, p2/p1 =
static temperature ratio, T2/T1 =
static density ratio, ρ2/ρ1 =
pt2/p1 =
gamma =

Oblique Shock

Select the input quantity. Then type the value of the desired quantity in the input box. Next, type the value of the upstream Mach number in its input box. Finally, click (or tap) the Compute button to display the output. Illegal values will be flagged with error messages.

Input Quantity Output data
Ramp angle, deg., δ =
Shock angle, deg, θ =
total pressure ratio, pt2/pt1=
static pressure ratio, p2/ p1 =
static temperature ratio, T2/T1 =
static density ratio, ρ2/ ρ1 =
pressure coeff., (p2-p1)/q =
downstream Mach number, M2 =
M1n =
gamma =

Rayleigh Flow

Select the input quantity. Then type the value of the desired quantity in the input box. Finally, click (or tap) the Compute button to display the output. Illegal values will be flagged with error messages.

Input Quantity Output data
Mach number, M =
total temperature ratio, Tt / Tt* =
static temperature ratio, T / T* =
static pressure ratio, p / p * =
total pressure ratio, Pt / Pt* =
velocity ratio, V / V* =
static density ratio, ρ / ρ* =
Smax / R =
gamma =

Fanno Flow

Select the input quantity. Then type the value of the desired quantity in the input box. Finally, click (or tap) the Compute button to display the output. Illegal values will be flagged with error messages.

Input Quantity Output data
Mach number, M =
static temperature ratio, T/T* =
static pressure ratio, P/P* =
total pressure ratio, Pt/Pt* =
density ratio, ρ / ρt =
velocity ratio, V / V* =
fLmax/D =
Smax/R =
gamma =

Atmosphere

1. Select the units. SI         US

2. Enter the altitude

3. Enter the Mach number

4. Click (or tap) the Compute button.